Aerodynamic drag can account for a majority of a vehicle's total fuel consumption at highway speeds. With a tractor towing a trailer, a gap exists between the tractor and trailer which tends to trap air, creating a low-pressure wake behind the tractor, resulting in a net pressure difference and, therefore, creating drag. One solution has been to use fixed side extenders and/or spoilers to reduce the effect of unwanted drag. Fixed side extenders are typically rigid, planar panels that extend rearward from the cab of the vehicle. Fixed side extenders are typically designed for specific trailer gap sizes and cannot be adjusted for different trailers and different driving conditions. Furthermore, fixed side extenders may be damaged when the truck is being towed in a backward direction.